All LDAP user attributes are imported and mapped to before created Custom Fields. (Big improvement to LP 6.0.6)everything works fine until I enable ldap.export.enabled = true. Afterwards even login fails with the following error:

1 211:29:33,871 ERROR [LoginAction:128] com.liferay.portal.ModelListenerException: javax.naming.directory.InvalidAttributeIdentifierException: [LDAP: error code 17 - : empty AttributeDescription]; remaining name 'uid=testuser,ou=people,dc=liferay,dc=com' 3com.liferay.portal.ModelListenerException: javax.naming.directory.InvalidAttributeIdentifierException: [LDAP: error code 17 - : empty AttributeDescription]; remaining name 'uid=testuser,ou=people,dc=liferay,dc=com' 4 at com.liferay.portal.model.UserListener.onAfterUpdate(UserListener.java:75) 5 at com.liferay.portal.model.UserListener.onAfterUpdate(UserListener.java:1) 6 at com.liferay.portal.model.BaseModelListener.onAfterUpdate(BaseModelListener.java:1) 7 at com.liferay.portal.service.persistence.impl.BasePersistenceImpl.update(BasePersistenceImpl.java:264) 8 at com.liferay.portal.service.impl.UserLocalServiceImpl.authenticate(UserLocalServiceImpl.java:5067) 9 at com.liferay.portal.service.impl.UserLocalServiceImpl.authenticateByScreenName(UserLocalServiceImpl.java:886)10 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)11 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)12 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)13 at java.lang.reflect.Method.invoke(Method.java:597)14 at com.liferay.portal.spring.aop.ServiceBeanMethodInvocation.proceed(ServiceBeanMethodInvocation.java:112)15 at com.liferay.portal.spring.transaction.TransactionInterceptor.invoke(TransactionInterceptor.java:71)16 at com.liferay.portal.spring.aop.ServiceBeanMethodInvocation.proceed(ServiceBeanMethodInvocation.java:108)17 at com.liferay.portal.spring.aop.ChainableMethodAdvice.invoke(ChainableMethodAdvice.java:59)18 at com.liferay.portal.spring.aop.ServiceBeanMethodInvocation.proceed(ServiceBeanMethodInvocation.java:108)19 at com.liferay.portal.spring.aop.ChainableMethodAdvice.invoke(ChainableMethodAdvice.java:59)20 at com.liferay.portal.spring.aop.ServiceBeanMethodInvocation.proceed(ServiceBeanMethodInvocation.java:108)21 at com.liferay.portal.spring.aop.ChainableMethodAdvice.invoke(ChainableMethodAdvice.java:59)22 at com.liferay.portal.spring.aop.ServiceBeanMethodInvocation.proceed(ServiceBeanMethodInvocation.java:108)23 at com.liferay.portal.spring.aop.ServiceBeanAopProxy.invoke(ServiceBeanAopProxy.java:211)24 at $Proxy96.authenticateByScreenName(Unknown Source)25 at com.liferay.portal.service.UserLocalServiceUtil.authenticateByScreenName(UserLocalServiceUtil.java:607)26 at com.liferay.portlet.login.util.LoginUtil.getAuthenticatedUserId(LoginUtil.java:160)27 at com.liferay.portlet.login.util.LoginUtil.login(LoginUtil.java:243)28 at com.liferay.portlet.login.action.LoginAction.login(LoginAction.java:189)29 at com.liferay.portlet.login.action.LoginAction.processAction(LoginAction.java:88)30 at com.liferay.portal.struts.PortletRequestProcessor.process(PortletRequestProcessor.java:175)31 at com.liferay.portlet.StrutsPortlet.processAction(StrutsPortlet.java:190)32 at com.liferay.portlet.FilterChainImpl.doFilter(FilterChainImpl.java:70)33 at com.liferay.portal.kernel.portlet.PortletFilterUtil.doFilter(PortletFilterUtil.java:48)34 at com.liferay.portlet.InvokerPortletImpl.invoke(InvokerPortletImpl.java:653)35...36Caused by: javax.naming.directory.InvalidAttributeIdentifierException: [LDAP: error code 17 - : empty AttributeDescription]; remaining name 'uid=testuser,ou=people,dc=liferay,dc=com'37 at com.sun.jndi.ldap.LdapCtx.mapErrorCode(LdapCtx.java:3110)38 at com.sun.jndi.ldap.LdapCtx.processReturnCode(LdapCtx.java:2987)39 at com.sun.jndi.ldap.LdapCtx.processReturnCode(LdapCtx.java:2794)40 at com.sun.jndi.ldap.LdapCtx.c_modifyAttributes(LdapCtx.java:1455)41 at com.sun.jndi.toolkit.ctx.ComponentDirContext.p_modifyAttributes(ComponentDirContext.java:255)42 at com.sun.jndi.toolkit.ctx.PartialCompositeDirContext.modifyAttributes(PartialCompositeDirContext.java:172)43 at javax.naming.directory.InitialDirContext.modifyAttributes(InitialDirContext.java:153)44 at com.liferay.portal.security.ldap.PortalLDAPExporterImpl.exportToLDAP(PortalLDAPExporterImpl.java:199)45 at com.liferay.portal.security.ldap.PortalLDAPExporterUtil.exportToLDAP(PortalLDAPExporterUtil.java:43)46 at com.liferay.portal.model.UserListener.exportToLDAP(UserListener.java:96)47 at com.liferay.portal.model.UserListener.onAfterUpdate(UserListener.java:72)48 ... 143 more

just in case it may help someone else, this error message seems to come up when liferay may be detecting an ldap attribute that it doesn't know what to do with. I think in my case, it was the 'memberOf' attribute. Removing that attribute via the Apache Directory Studio (make sure the Fetch Operational Attributes option in the right-click context menu is turned on) resolved it when i was testing stuff out.